1. Field of the Invention
The present invention, hereof, relates to a portable terminal which is capable of a wireless voice telephone and an internet terminal for text data communication as well as a video camera (both for still picture and for moving picture).
2. Description of the Related Art
Key driving forces of information technology innovation in contemporary human life have been a personal computer (PC) for internet access and a wireless telephone (cellular phone), which are capable of wireless communication in any mobile circumstance.
The PC was used as an equipment for calculation, data processing and controlling at the early stage of its usage.
In addition to those applications, at present, the role of the PC as an internet terminal has significantly increased.
Portable terminals are categorized into wired type and wireless type in terms of with or without telecommunication lines. The types of signals that a user sends and receives by a terminal are, (1) audio or voice data used in a wireless telephone, (2) text data mainly used in emails of internet access and (3) video data used in a video camera.
Portable terminals, which are capable of wireless communication in mobile environment, are categorized into three forms in terms of man-machine-interface; handling and/or manipulating capability as follows.                (1) Voice communication by use of a portable terminal handled by one side hand of the user.        (2) Emailing for internet communication manipulated by fingers of both his hands pushing keyboards on the portable terminal.        (3) Taking pictures by holding the terminal as a video camera at both edge sides of the terminal with both his hands and by operating a button such as a shutter by use of one finger of his hand.        
From man-machine-interface viewpoint, the PC is easy to use for the purpose as an internet terminal because it is capable of inputting text data of email since it has more than 50 keys (for alphabet characters, numerical characters, marks and functions) on the keyboard. One of the typical form in its usage is that a user opens the two panels facing their longer front sides toward him and that he manipulates its keys by fingers of his both hands.
However, the PC has been differently used for voice communication from the wireless telephone because of its larger size, heavier weight, and higher power consumption. In other words, a physical form for voice communication is significantly different from that of the wireless telephone because it is very difficult to hold the PC by his single hand. Hence, in using the PC as a voice communication terminal, he is optionally forced to use a microphone, a speaker, an earphone, or an overhead microphone/speaker on his head and face, which are optionally attached to the PC.
These kinds of usage are troublesome to him from man-machine-interface viewpoint.
On the contrary, voice communication is conventionally carried out by using the wireless telephone, which is composed of the two piece of panels with a hinge unit attached on their edge sides. One of a typical form in its usage is that a user opens the two panels facing the shorter front sides toward him and that he rotates the two panels around the center axis of the hinge unit by which the length of the telephone is extended almost as long as the length between his mouth and his ear. He can hold the telephone by his single hand because its width (length of the shorter front side) and its thickness are small enough to fit the size of his hand and fingers. Another typical form of a-wireless telephone in use of voice communication is that a user slides two panels so as to extend its length sufficient enough to the length mentioned above.
However, the telephone is too small to accommodate the sufficient numbers (over 50) of keys (covering full English alphabet characters; 26, for example) on its panels for the purpose of inputting text data in emailing communication which is essential as an internet terminal.
Known is a wireless telephone having some unique mechanism by which the telephone is used as a camera as well as a telephone [reference 1] considering man-machine-interface.
[reference 1]: United States Patent Application, Shibata et al, PORTABLE TERMINAL, Pub. No, US 2001/0004269 A1, Pub, Date: Jun. 21, 2001
In this disclosed art, the mechanism has a linked mechanisms having two freedom of rotation; X and Y direction. That is, in use of a camera, a user rotates two panels of the telephone in Y direction after he opens them by rotating it in the X direction.
Also known is a terminal which accommodates about 60 keys (alphabetical characters, numerical characters, marks and functions) with rotating mechanism and facilitates inputting text data for internet access such as emailing in addition to wireless vice telephone function. However, the terminal accommodates additional keys (10 numerical keys and some function keys for wireless voice telephone to the about 60 keys above mentioned, resulting in that the terminal becomes thicker and heavier.
To summarize all of those previous arts, portable terminals so far only have either slide mechanism or rotate mechanism in its hinge unit, resulting in some deficit from man machine interface standpoint.